The NFL was formed in 1920 as the American Professional Football Association (APFA) before renaming itself the National Football League for the 1923 season. The NFL agreed to merge with the American Football League (AFL) in 1966, and the first Super Bowl was held at the end of that season; the merger was completed in 1970. Today, the NFL has the highest average attendance (67,591) of any professional sports league in the world<ref name="NFL is world's best attended pro sports league">{{#invoke:citation/CS1|citation
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